Diacylglycerol Kinase Delta (DGKd)

DGKd encodes a cytoplasmic enzyme that phosphorylates diacylglycerol to produce phosphatidic acid. DGKD2 originates from an upstream first exon relative to that utilized by the original clone, called DGKD1, and translation of DGKD2 begins at an alternate upstream initiation methionine. The deduced 1,214-amino acid protein has a calculated molecular mass of 135 kD, and its N terminus contains proline-rich and glu/asp-rich sequences not found in DGKD1. RT-PCR detected DGKD2 in all human normal and tumor tissues and cell lines examined, with highest expression in testis, peripheral blood leukocytes, and several tumor tissues. DGKD2 expression was high in ovary, lower in spleen, and much weaker in tumor tissues and cell lines. Western blot analysis showed that protein levels reflected the mRNA levels for the 2 isoforms.